Antimicrobial bioactive glass for treatment of traumatic or pathological bone defects
Project C
Confocal image of SaOS-2 (osteoblast-like) cells
Image: Julius Trautmann
Implant-associated infections remain a major challenge in bone regeneration and frequently lead to implant failure. This project investigates how bioactive glass (BG) particles can simultaneously support bone cell growth while limiting bacterial colonization. Beyond well-established chemical effects such as ion release, we examine how particle surface features physically interact with microbes at a micro- and nanoscale. By combining advanced imaging and molecular analysis, our goal is to design BG materials that selectively inhibit bacteria while promoting osteoblast activity.
Bioactive glass granules are widely used in bone regeneration due to their ability to stimulate bone-forming cells. At the same time, they exhibit antimicrobial properties, although the underlying mechanisms remain incompletely understood. In this project, we investigate how BG particles influence both bacteria and osteoblast-like cells under controlled conditions. Particular emphasis is placed on distinguishing chemical effects, such as pH changes and ion release, from physical interactions driven by particle surface features. Using complementary techniques, including fluorescence microscopy, flow cytometry, and high-resolution STED microscopy, we quantify cell viability and visualize particle–cell interactions at the nanoscale. In parallel, proteomic analyses provide insight into cellular response pathways. This integrated approach advances our understanding of biomaterial behaviour in complex biological environments and supports the development of safer, more effective materials for clinical applications.
Overview of project C
Image: Dr. V. Horbert, J. Trautmann, A. Atta, H. Garlipp & B. Samuel
Left/centre: Glass melting, right: Bioactive glass 45S5
Image: Jens Meyer (University of Jena)Research Highlights
Highlight 1: Particle-Induced Measurement Bias Identified
We demonstrate that BG particles can interfere with fluorescence-based viability assays, potentially distorting biological readouts. By systematically comparing fluorescence microscopy and flow cytometry, we identify key sources of bias and establish improved strategies for accurate and reproducible data interpretation.
Highlight 2: Bioactive glass atomic-scale features controlling bioactivity identified also in soda-lime silicate glasses
Structural analysis using solid-state NMR and Raman spectroscopy allowed identification of key structural features which allow silicate glasses to become bioactive materials, and results show that many of these features present in typical BG compositions can also be identified in simple soda-lime glasses of low silica content.
Highlight 3: Evidence for Combined Antimicrobial Mechanisms
Our findings show that BG antimicrobial activity cannot be explained by pH changes alone. Instead, a combination of ion release and direct particle–microbe interactions supported by high-resolution imaging contributes to bacterial inhibition, pointing to a more complex and tunable mechanism.
Related Publications
Samuel, B.J., Jin, Z., Brauer, D.S., Matziolis, G., and Horbert, V. (2025)
Evaluating cell viability assessment techniques: a comparative study of flow cytometry and fluorescence microscopy in response to bioactive glass exposure
BioMedical Engineering OnLine 24, 112. https://doi.org/10.1186/s12938-025-01452-yExternal link
Jin, Z., Neuville, D.R., and Brauer, D.S. (2025)
Glasses for bone regeneration: structural features controlling physical properties and ion release of bioactive glasses 45S5, S53P4 and 13-93
RSC Advances 15, 4997. https://doi.org/10.1039/D4RA06081DExternal link
Jin, Z., Neuville, D.R., Chartier, C., Kachanov, P., Kroeker, S., Gin, S., Du, J., and Brauer, D.S. (2025)
From Window panes to bone regeneration: Structure, viscosity and bioactivity of soda lime silicate glasses
J Mater Chem B 13, 3448. https://doi.org/10.1039/d4tb02414aExternal link
Su, M., Ergin, M., Horkavcová, D., Horbert, V., Matziolis, G., and Brauer, D. S. (2025)
Beyond bioactive glass composition: Using morphology to improve in vitro and in vivo performance
Adv Healthc Mater 14, e02591. https://doi.org/10.1002/adhm.202502591External link
Project Team
Prof. Dr. Delia S. Brauer
Friedrich Schiller University Jena · Bioactive Glasses
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Prof. Dr. Georg Matziolis
Waldkliniken EisenbergExternal link
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Dr. Victoria Horbert
Waldkliniken Eisenberg · Experimental OrthopedicsExternal link
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Abdellah Atta
Waldkliniken Eisenberg · Experimental OrthopedicsExternal link
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Zhaorui Jin
Friedrich Schiller University Jena · Bioactive Glasses
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Bolaji Samuel
Waldkliniken Eisenberg · Experimental OrthopedicsExternal link
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Meixin Su
Friedrich Schiller University Jena · Bioactive Glasses
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Dr. Leandra Bauer
Waldkliniken Eisenberg · Experimental OrthopedicsExternal link
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Matthias Brensing
Waldkliniken Eisenberg · Experimental OrthopedicsExternal link
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Dr. Coraline Chartier
Friedrich Schiller University Jena · Bioactive Glasses
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Shaher Bano Zaidi
Friedrich Schiller University Jena · Bioactive Glasses
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